| 1. |
- Björkesten, Johan, et al.
(författare)
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Stability of Proteins in Dried Blood Spot Biobanks.
- 2017
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Ingår i: Molecular & Cellular Proteomics. - 1535-9476 .- 1535-9484. ; 16:7, s. 1286-1296
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Tidskriftsartikel (refereegranskat)abstract
- An important motivation for the construction of biobanks is to discover biomarkers that identify diseases at early, potentially curable stages. This will require biobanks from large numbers of individuals, preferably sampled repeatedly, where the samples are collected and stored under conditions that preserve potential biomarkers. Dried blood samples are attractive for biobanking because of the ease and low cost of collection and storage. Here we have investigated their suitability for protein measurements. 92 proteins with relevance for oncology were analyzed using multiplex proximity extension assays (PEA) in dried blood spots collected on paper and stored for up to 30 years at either +4°C or -24°C. Our main findings were that 1) the act of drying only slightly influenced detection of blood proteins (average correlation of 0.970), and in a reproducible manner (correlation of 0.999), 2) detection of some proteins was not significantly affected by storage over the full range of three decades (34% and 76% of the analyzed proteins at +4°C and -24°C, respectively), while levels of others decreased slowly during storage with half-lives in the range of 10 to 50 years, and 3) detectability of proteins was less affected in dried samples stored at -24°C compared to at +4°C, as the median protein abundance had decreased to 80% and 93% of starting levels after 10 years of storage at +4°C or -24°C, respectively. The results of our study are encouraging as they suggest an inexpensive means to collect large numbers of blood samples, even by the donors themselves, and to transport, and store biobanked samples as spots of whole blood dried on paper. Combined with emerging means to measure hundreds or thousands of protein, such biobanks could prove of great medical value by greatly enhancing discovery as well as routine analysis of blood biomarkers.
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| 2. |
- Bonnier, Gaga, et al.
(författare)
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Kirunas Framtid - Kan man flytta en stad? : restaureringskonst på sin spets
- 2010
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Rapport (populärvet., debatt m.m.)abstract
- Ar 2004 konstaterade gruvbolaget LKAB att en på världsmarknaden ökad efterfrågan på järnmalm innebär att marken ovanför brytningsområdet i Kiruna spricker i takt med att malmen bryts. Detta deformationsområde kommer att omfatta större delen av den gamla staden inklusive kyrkan och stadshuset. Osäkerheten är stor om hur man skall gå till väga och de konkreta frågorna är ännu obesvarade. Diskussionen handlar om vart man skall flytta och den pendlar mellan ytterligheterna att helt avstå från det gamla och bygga helt nytt eller skapa ett nytt område med de gamla husen musealt återuppbyggda i ett landskapssammanhang som så långt möjligt påminner om det gamla. Den avgörande frågan är, menar vi, hur staden och dess invånare kan behålla sin identitet och sitt minne - framtiden för kulturmiljön i vidaste bemärkelse.Omvandlingen och den successiva flytten av Kirunas centrala delar är en av de riktigt stora samhällsbyggnads- och bevarandefrågorna i vår samtid, en samhällsförändring med global räckvidd - restaureringskonst på sin spets.
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| 3. |
- Caja, Laia, et al.
(författare)
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Snail regulates BMP and TGF beta pathways to control the differentiation status of glioma-initiating cells
- 2018
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Ingår i: Oncogene. - : Springer Science and Business Media LLC. - 0950-9232 .- 1476-5594. ; 37:19, s. 2515-2531
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Tidskriftsartikel (refereegranskat)abstract
- Glioblastoma multiforme is a brain malignancy characterized by high heterogeneity, invasiveness, and resistance to current therapies, attributes related to the occurrence of glioma stem cells (GSCs). Transforming growth factor beta (TGF beta) promotes self-renewal and bone morphogenetic protein (BMP) induces differentiation of GSCs. BMP7 induces the transcription factor Snail to promote astrocytic differentiation in GSCs and suppress tumor growth in vivo. We demonstrate that Snail represses stemness in GSCs. Snail interacts with SMAD signaling mediators, generates a positive feedback loop of BMP signaling and transcriptionally represses the TGFB1 gene, decreasing TGF beta 1 signaling activity. Exogenous TGF beta 1 counteracts Snail function in vitro, and in vivo promotes proliferation and re-expression of Nestin, confirming the importance of TGFB1 gene repression by Snail. In conclusion, novel insight highlights mechanisms whereby Snail differentially regulates the activity of the opposing BMP and TGF beta pathways, thus promoting an astrocytic fate switch and repressing stemness in GSCs.
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| 4. |
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| 5. |
- Ebai, Tonge, et al.
(författare)
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Analytically Sensitive Protein Detection in Microtiter Plates by Proximity Ligation with Rolling Circle Amplification
- 2017
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Ingår i: Clinical Chemistry. - : Oxford University Press (OUP). - 0009-9147 .- 1530-8561. ; 63:9, s. 1497-1505
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Detecting proteins at low concentrations in plasma is crucial for early diagnosis. Current techniques in clinical routine, such as sandwich ELISA, provide sensitive protein detection because of a dependence on target recognition by pairs of antibodies, but detection of still lower protein concentrations is often called for. Proximity ligation assay with rolling circle amplification (PLARCA) is a modified proximity ligation assay (PLA) for analytically specific and sensitive protein detection via binding of target proteins by 3 antibodies, and signal amplification via rolling circle amplification (RCA) in microtiter wells, easily adapted to instrumentation in use in hospitals.METHODS: Proteins captured by immobilized antibodies were detected using a pair of oligonucleotide-conjugated antibodies. Upon target recognition, these PLA probes guided oligonucleotide ligation, followed by amplification via RCA of circular DNA strands that formed in the reaction. The RCA products were detected by horseradish peroxidase-labeled oligonucleotides to generate colorimetric reaction products with readout in an absorbance microplate reader.RESULTS: We compared detection of interleukin (IL)-4, IL-6, IL-8, p53, and growth differentiation factor-15 by PLARCA and conventional sandwich ELISA or immuno RCA. PLARCA detected lower concentrations of proteins and exhibited a broader dynamic range compared ELISA and iRCA using the same antibodies. IL-4 and IL-6 were detected in clinical samples at femtomolar concentrations, considerably lower than for ELISA.CONCLUSIONS: PLARCA offers detection of lower protein levels and increased dynamic ranges compared to ELISA. The PLARCA procedure may be adapted to routine instrumentation available in hospitals and research laboratories.
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| 6. |
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| 7. |
- Franzen, Bo, et al.
(författare)
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A fine-needle aspiration-based protein signature discriminates benign from malignant breast lesions
- 2018
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Ingår i: Molecular Oncology. - : Wiley. - 1574-7891 .- 1878-0261. ; 12:9, s. 1415-1428
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Tidskriftsartikel (refereegranskat)abstract
- There are increasing demands for informative cancer biomarkers, accessible via minimally invasive procedures, both for initial diagnostics and to follow-up personalized cancer therapy. Fine-needle aspiration (FNA) biopsy provides ready access to relevant tissues; however, the minute sample amounts require sensitive multiplex molecular analysis to achieve clinical utility. We have applied proximity extension assays (PEA) and NanoString (NS) technology for analyses of proteins and of RNA, respectively, in FNA samples. Using samples from patients with breast cancer (BC, n=25) or benign lesions (n=33), we demonstrate that these FNA-based molecular analyses (a) can offer high sensitivity and reproducibility, (b) may provide correct diagnosis in shorter time and at a lower cost than current practice, (c) correlate with results from routine analysis (i.e., benchmarking against immunohistochemistry tests for ER, PR, HER2, and Ki67), and (d) may also help identify new markers related to immunotherapy. A specific 11-protein signature, including FGF binding protein 1, decorin, and furin, distinguished all cancer patient samples from all benign lesions in our main cohort and in smaller replication cohort. Due to the minimally traumatic sampling and rich molecular information, this combined proteomics and transcriptomic methodology is promising for diagnostics and evaluation of treatment efficacy in BC.
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| 8. |
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| 9. |
- Hammond, Maria, et al.
(författare)
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Sensitive detection of aggregated prion protein via proximity ligation
- 2014
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Ingår i: Prion. - : Informa UK Limited. - 1933-6896 .- 1933-690X. ; 8:3, s. 261-265
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Tidskriftsartikel (refereegranskat)abstract
- The DNA assisted solid-phase proximity ligation assay (SP-PLA) provides a unique opportunity to specifically detect prion protein (PrP) aggregates by investigating the collocation of three or more copies of the specific protein. We have developed a SP-PLA that can detect PrP aggregates in brain homogenates from infected hamsters even after a 10(7)-fold dilution. In contrast, brain homogenate from uninfected animals did not generate a detectable signal at hundred-fold higher concentration. Using either of the two monoclonal anti-PrP antibodies 3F4 and 6H4 we successfully detected low concentrations of aggregated PrP. The presented results provide a proof of concept that this method might be an interesting tool in the development of diagnostic approaches of prion diseases.
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